Interaction of internalin with E-cadherin promotes entry of Listeria monocy
togenes into human epithelial cells. This process requires actin cytoskelet
on rearrangements. Here we show, by using a series of stably transfected ce
ll lines expressing E-cadherin variants, that the ectodomain of E-cadherin
is sufficient for bacterial adherence and that the intracytoplasmic domain
is required for entry. The critical cytoplasmic region was further mapped t
o the beta-catenin binding domain. Because beta-catenin is known to interac
t with alpha-catenin, which binds to actin, we generated a fusion molecule
consisting of the ectodomain of E-cadherin and the actin binding site of al
pha-catenin. Cells expressing this chimera were as permissive as E-cadherin
-expressing cells. In agreement with these data, alpha- and beta-catenins a
s well as E-cadherin clustered and colocalized at the entry site, where F-a
ctin then accumulated. Taken together, these results reveal that E-cadherin
, via beta- and alpha-catenins, can trigger dynamic events of actin polymer
ization and membrane extensions culminating in bacterial uptake.